Telephone system.



L. H. JOHNSON. TELEPHONE SYSTEM.

APPLICATlON men JAN. 22, 1915.

Patented July 2, 1918..

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I give rinrrnn .s'rnrns ATENT onsron.

LEWIS H. JOHNSOLT, OFBLOOMFIELD, NEW Jun MENTS, TO WESTERN ELECTRIC eoivrrAivy, mooaroiae'rnn,

.NEW YORK.

SEY, AssIGNoR, BY MESNE ASSIGN- A. CORPORATION OF TELEPHQNE .srsrsm- Patented July 2, 1913'.

Application filed January 22, 1915. serial No. 3,666.

To all whom it may concern:

Be it known that I, Lnwrs H. JOHNSON, a citizen of the United States, residing at Bloomfield, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone systems, and more particularly to such systems which are used for interconnecting common battery and magneto Or local battery lines terminating at a central oflice.

The object of this invention is the production of improved signaling. means for such telephone systems.

In accordance with one feature of this invention a universal cord circuit is provided with a signaling device capable of giving a plurality of signals of different manifestations, and means for causing said device to a signal of one manifestation whenthe cord circuit is connected with a common battery line, and a signal of another manifestation when the cord circuit is connected with a magneto or local battery line.

This invention is illustrated in the accompanying drawing in which all apparatus is shown in its normal and unactuated condition.

There is shown in the drawing a telephone system containing one embodiment of this invention and comprising subscribers stations A and B, terminating at a central ofiice, and a-universalcord circuit C located thereat for interconnecting the subscribers stations. It will be understood that a plurality of stations similar to stations A and B terminate at the central office, but for sake of simplicity only the two stations are shown. Station A is of the magneto type, while station B is of the common battery type. The universal cord circuit may be used indiscriminately to connect two ma neto telephone lines, two common battery lines, a magneto with a common battery line or a common battery with a magneto line. It is believed that this invention will be fully understood from a description of the operation of the system shown in the drawing, and it will be so described.

Supposing subscriber A wishes to converse with subscriber B, A will operate hand generator 1 in the usual manner, causing a flow of current through'winding 6 of line the relay 21 will not be actuated.

the tip of the calling .a jack corresponding to calling plug and the jack the cut-off relay34, to ground. Current in vand 37 and actuates relay 7 traced from generator 1, contact 2 thereof, line wire 3, contact 4 of cut-off relay 5, winding6 of line relay 7, contact 8 of cut-ofi' relay 5, and line wire 9 to generator 1. Current in this path energizes line relay 7, which looks up over a path from the live pole of battery 15, winding 16, of line relay 7, contact 17 thereof and contact 18 of cutoff relay 5, to ground, and completes a circuit for line signal 19. The operator, observing the line signal 19, inserts the answering plug in the ack indicated by the line signal 19, and thereby completes a circuit from'the live pole of battery 20, Winding of marginal relay 21, sleeve strand 22 of the cord circuit, sleeve contact 23 of the answering-jack and the windings of the cutoff relay 5, to ground. Current in this path actuates the cut-oil relay 5, which removes the line relay 7 from the line wires 3 and 9,

opens the locking circuit of the line relay 7 and eft'aoes the line signal 19, but since the cut-off relay 5 has a high resistance winding and relay 21 a low resistance winding,

The operator actuates listening key 24, connecting operators telephone set across strands 25 and 26 of the cord circuit, and

"asks the desired number of the calling subscriber. Finding the desired number to be that of subscriber B, the operator touches plug to the sleeve of t I Bs line to determine the idle or busy condition thereof. If the line tests idle, the calling plug is inserted in the jack, completing a circuit from the live pole of battery. 30, winding of marginal relay 31, sleeve contacts 32 and 33 of the and windings of this path actuates the cut-off relay 34, cutting line relay 35 from line conductors 36 i the relay 31. Actuation of relay 31 connects the live pole of battery 40 through contact 41 of relay 31, and one winding of relay 42 to the talking strand 26, connects ground through contact 43 of relay 31, and the other winding of relay 42 to the talking strand 25, and completes a circuit from the live pole of battery 44, through supervisory signal 45, contact .46 of relay 42 and contact 47 of relay 31, to ground, operating the supervisory signal 45, which remains. operated until the removal @t the recei er f om t e swite he k y S talking scriber B, as hereinafter more fully ex plained. The operator now restores the listening key 24 to its normal position and actuates the ringing key 48, opening the talking strands 25 and 26 of the cord circuit and connecting a source of ringing current 49 to ring contact 50 of the calling plug and ground to tip contact 5].. The path for the ringing current through the called subscr1bers ringer is from 49, to ring contacts 50 and .52 of the calling plug and the jack, line wire 36, condenser 53, ringer 54, line wire 37, and tip cont-act's 55 and 51 of the j aek and the callingplug, to ground. After ringing the called subscriber, the operator restores ringing key 48 to its normal position. In response to the sounding of the ringer 54, due to the passage of ringing current therethrough, subscriber B removes the receiver from the. switchhook, thereby completing a circuit from the live pole of battery 40, contact 41 of relay 31, one Winding of relay 42, talking strand 26, ring contacts 50 and 52 of the calling plug and the jack line wire 36, transmitter 56, switchhook contact 57, line wire 37, tip contacts 55 and 51 ofthe jack and the calling plug, talking strand 25, other winding of relay 42, and contact-43 of relay 31, to ground. Current in this path actuates relay 42, opening contact 46 thereof and effacing the supervisory signal 45.

Upon finishing the conversation, subscribers A and B restore the respective receivers to the switchhooks. The restoration of Bsreceiver opens the circuit of relay 42 at switchhook contact 57, whereupon relay 42 is deenergized and contact 46'thereof is closed, completing the circuit for the supervisory signal 45 and furnishing a disconnect signal to the operator from subscriber B. When subscriber A restored the receiver to the ,switchhook, no apparatus was afi'ected thereby. To give a disconnect signal, subscriber A operates the hand generator 1 in the usual manner, causing a flow of current through the windings of relay 60, traced from generator 1, line wire 3, ring contacts 61 and 62 of answering jack and plug, talking strand 63, one winding of relay 60, contact 64 of relay 21, other winding of relay 60, talking strand 65, tip contacts 66 and 67 of the answering plug and jack and line wire 9 to generator 1. Current in this path actuates relay 60, whichv opens normally closed contact 68 and closes normally open contact 69 thereof, completing a circuit from the live pole of battery 75, supervisory signal 7 6, contact 69 of relay 60, winding of relay 77, and contact 78 of relay 21, to ground. Current in this path actuates relay 7 7 which completes a locking circuitfor itself from the live pole of battery 80, contact 81 of the listening key 24, contact 82 and the winding of relay 77, and

contact 78 of relay 21 to ground, and completes a circuit from the live pole of battery 75, supervisory signal 76, contact 83 of relay 77 and interrupter 84, toground. The interrupter 84 causes the supervisory signal 76 to flash at regular intervals, thereby furnishing the operator with a disconnect signal from subscriber A. The supervisory signal 76 will continue to flash until the operator removes the answering plug from the jack, or operates the listening key 24 to open the normally closed contact 81 thereof, Which opens the locking circuit of relay 77 which releases and efl'aces supervisory signal 76. It is to be noted that relay 60 remains actuated only so long as the generator 1 is being actuated, (which, for a disconnect, is usually a very short time) and the energizing circuit for relay 77 is therefore closed for only a very short time.

It is to be understood that both ends of the cord circuit are similarly equipped, the supervisory signal 76 corresponding with 45, relay 21 with 31, relay 60 with .42, and relay 77 with 85. To prevent the passage of battery from one end of the cord circuit to the other, talking strands 25 and are joined through a condenser 86, and talking strands 26 and 63 are likewise joined through a condenser 87. It will be understood therefore, without any further description, that the answering end of the cord circuit, when connected with a common battery line, will function in the same manner as does the calling end when connected with such a line; and similarly, the calling end, when connected with a magneto line, will function in the same manner as does the answering end, when connected with such a line. WVhile in this description various batteries have been referred to, it is to be understood that a common battery may be substituted for all of these, and such is the usual practice.

In telephone systems heretofore used, when the cord circuit is connected with a common battery telephone line, the supervisory signal is under the control of the subscribers switchhook, so that the signal is not operated during conversation, and is operated when the subscriber has restored pervisory signal flashes in accordance with the movement of the switchhook. When the cord circuit is connected with a magneto telephone line, the only way for the subscriber to signal the operator is to operate the supervisory signal to give a steady light, which is the disconnect signal from both the common battery and magneto subscriber. Due to this condition in the case of systems wherein'both magneto and common battery lines terminate at the same office-and the same cord circuit is used to connect such lines, and since an operator is not able to distinguish between magneto and common battery lines, it frequently oc curs that a magneto line is disconnected when in reality the subscriber connected therewith has been operating the associated,

generator to make a recall or to initiate a call. It will be seen therefore that considerable delay is occasioned before the subscriber gets the attention of the operator. This condition results in another very serious disadvantage. Before the called com mon battery subscriber answers, the supervisory signal associated with the connected cord burns steadily. Likewise when a connected magneto subscriber rings, the supervisory signal burns steadily. Consequently, when the operator is very busy, she frequently forgets whether the signal denotes that a common battery subscriber has not responded or that a magneto subscriber has rung, and thinking that the subscriber has not responded again presses the-ringing key. Now if the subscriber has the receiver off the hook to initiate a call, when the operator presses the ringing key, the resulting effect upon the ear-drum of the subscriber will be very disagreeable. It will be seen therefore that, in telephone systems employing the so-called Universal cord circuit, it is very important that the operator be able to distinguish between the disconnect signals of the magneto and common battery lines, in order that the disadvantages hereinbefore mentioned may be overcome. The present invention accomplishes this result and provides a system of signals of such a character thatv when the supervisory signal flashes, the operator knows that she must challenge. In'providing the improved signaling system of this invention, the many disadvantages of the old cumbersome and time consuming scheme heretofore used and hereinbefore described, are overcome.

Vhat is claimed is:

1. A telephone system comprising common battery and local battery telephone lines terminating-at a central ofiice, a link cir cuit thereat for intercomiecting the lines, a signalingdevice for the link circuit, asource of current and interrupter mechanism at the central ofiice, a local relay for the link circuit, a relay therein controlled over a connected line of either character and cooper-at ing with the local relay when controlled from] a common battery line for including the source of current in circuit with the-signaling device to furnish a continuous signal, and a third relay in the link circuit energized upon the energization of the secondmentioned relay when controlled from a local battery line and cooperating with the first relay to include the source of current and interrupter mechanism in circuit with the signaling device to furnish an intermittent signal.

2; A telephone system comprising common battery and local battery telephone lines terminating at a central oflice, a link ircuit thereat for interconnecting the lines, a signaling device for the link circuit, a local relay for the link circuit, a relay there.- in controlled over a connected line of either character, an operating circuit for the s1g-- naling device including a contact of the local relay established upon the denergization of the second-mentioned relay when controlled from a common battery line, a third relay in the link circuit energized upon the energization of the second-mentioned relay when controlled from a local battery line, a second operating circuit for the signaling device establishedupon the energization of the third relay, and means associated with one of the operating circuits and effective upon the closure thereof to cause the signaling device to furnish a signal differing in character from that furnished when the other operating circuit is closed.

'3. A telephone exchange system comprising common batter and local battery telephone lines terminating at a central office, a link circuit thereat for interconnecting the lines, a signaling device in the link circuit, a local relay in the link circuit responsive to the connection thereof with a line of one character but nonresponsive when connected with a line of the other character, a relay in the link circuit controlled over a telephone line of either character, an operating circuit for the signaling device controlled by both relays and established upon the deenergization of the second relay when controlled from a connected common battery line, a third relay for the link circuit "energized upon the energization of the second relay whencontrolled over a connected local battery line, a second operating circult for the signalingdevice established upon the energization of the third relay, and means associated with one of the operating circuits and effective upon the closure thereof to cause the signaling device to furnish a sign'al differing in character from that furnished upon the closure of the other operat ing circuit.

l. A telephone system comprising common battery and magneto telephone lines terminating at a central oflice, link conductors thereat for interconnecting said lines, a signaling device thereat adapted to give a plurality of signals of different manifestations, relays associated with said link conductors, and a relay bridged across said link conductors controlled by direct current over a connected common battery line for causing said bridged relay to cooperate with one of said associated relays to cause said device to give a signal of one manifestation, and controlled by alternating current over a connected magneto line for causing said bridged relay to cooperate with another of said associated relays to cause said device to give a signal of a different manifestation.

5. A telephone system comprising common battery and magneto telephone lines terminating at a central ofiice, link conductors thereat for interconnecting said lines, a signaling device adapted to give a plurality of signals of different manifestations associated with said link conductors, a relay associated therewith and actuated upon connection with one of said common battery lines, a second relay associated with said linkconductors and adapted to cooperate With said first mentioned relay, means associated with each of said common battery lines for controlling the cooperation of said relays to cause said device to give a signal of one manifestation, a third relay associated with said link conductors and adapted to cooperate with said second relay when said link conductor and one of said magneto lines are connected, and means associated with each of said magneto lines for controlling the cooperation of said second and third relays to cause said device to give a signal of different manifestation.

6.. A telephone system comprising common battery and magneto telephone lines terminating at a central oflice, link conductors thereat for interconnecting said lines, a signaling device, a source of current and an interrupter at the, central office, a relay associated with said link conductors and actuated when said link conductors are connected with one of said common battery lines, a relay bridged across said link conductors, means associated with each of said common battery lines for controlling the operation of said bridged relay for completing a circuit including said device and said source of current, a third relay associated with said link conductors and controlled by said bridged relay when said link conductorsare connected with one of said magneto lines, and means associated with each of said magnetolines for controlling the operation of said bridged relay to cause said third relay to complete a circuit including said device, said source of current and said interrupter.

7. A telephone system comprising telephone lines terminating at a central oflice, a link circuit connected with one of the lines, a signaling device, a source of current and interrupter mechanismat the central oflice, a

mechanism in circuit with vice to furnlsh an intermittent signal.

relay associated with the link circuit and controlled over the connected line, a second relay operated upon the energization of the first relay to include the source of current and interrupter mechanism in circuit with the signaling device, and a locking circuit for the second relay established upon the operation thereof.

-8. A telephone system comprising magneto telephone lines terminating in a central oflice, a link circuit connected with one of the lines, a signaling device, a source of cur rent and interrupter mechanism at the central office, a relay associated with the link circuit and controlled by alternatin current over the connected line, a second re ay operated upon the energization of the first relay to include the source of current and inter rupter mechanism in circuit with the signaL ing device, and a locking circuit for the sec ond relay established upon the operation thereof, whereby the second relay is removed from the control of the first relay.

9. A telephone system comprising common battery and magneto telephone lines terminating at a central office, a link circuit thereat for interconnecting the lines, a signaling device, a source of current and interrupter'mechanism at the central office, a relay operating upon connection of the link circuit with a common battery line and not operating upon connection with a magneto line, a second relay controlled over a line of either character and cooperating with the first mentioned relay when energized to include the source of current in circuit with the signaling device to furnish a continuous signal, and'a third relay actuated upon the energization of the second relay when the first relay is deenergized and cooperating With the first relay when denergized to include the source of current and interrupter the signaling de 10. A telephone exchange system comprising common battery and magneto telephone lines terminating at a central ofl'ice, a link circuit thereat for interconnecting the lines, a signaling device for the link circuit, a relay in the link circuit responsive to the connection thereof with a line of one character but non-responsive when connected to a line of the other character, a relay in the vlink circuit responsive to direct current when controlled from a connected common battery line and responsive to alternating current when controlled from a connected magneto line, an operating circuit for the signaling device established through the cooperation of the relays when the second relay is controlled from a connected common battery line, a third relay in the link circuit controlled by the second relay when operatively responsive to alternating current, a second operating circuit for the Slg-- naling device controlled by the third relay, and means associated with one of the operating circuits and effective upon the closure thereof to cause the signaling device to furnish a signal differing in character from that furnished when the other operating circuit is closed.

11. A telephone exchange system comprising common battery and magneto tele: phone lines terminating at a central office,

a link circuit thereat for interconnecting the lines, a signaling device for the link circuit, a relay in the link circuit energized upon the connection thereof with a common battery line and not energized when connected with a magneto line, a relay in the link circuit responsive to direct current when controlled from a connected common battery line and responsive to alternating current when controlled from a connected magneto line, an operating circuit for the signaling device es- Copies of this patent may be obtained for ing device five cents each,

tablished upon the denergization of the second relay when controlled from a common battery line while the first relay is energized, a third relay in the link circuit responsive to the energization of the second relay when controlled from a connected magneto line, a second operating circuit for the signaling device established upon the response of the third relay, and means associated with the second operating circuit and effective upon the closure thereof to cause the signalto furnish a signal differing in character from that furnished when the first operating circuit is closed.

In Witness whereof, I hereunto subscribe my name this th day of January,

LEWIS H. JOHNSON. Witnesses:

E. EDLER, K. L. STAHL.

by addressing the Commissioner of Iatents.

Washington, D. G. 

